The present invention is directed to a system and method for creating a pattern for at least one antenna and/or a frequency selective surface. More particularly, the present invention is directed to a system and method for creating a pattern for at least one antenna and/or a frequency selective surface using a genetic algorithm.
Fractal patterns have been discovered to be useful for generating antenna patterns. In the past, fractal patterns have been arbitrarily selected for antennas, and the radiation results determined. Depending on the radiation results, either the selected pattern was used for the antenna, or another pattern was selected.
A problem with this “trial and error approach” is that there are infinitely many types of possible fractal antenna configurations. Even within the same class of fractal antennas, there may be an extremely large number of possible variations of the shape. Thus, arbitrarily selecting fractal patterns may be a cumbersome and inefficient process. Also, this approach does not guarantee that the resulting fractal antenna has desired radiation characteristics but rather typically results in a fractal antenna design that is suboptimal.
Various other types of devices may also benefit from a procedure for optimizing patterns of elements. For example, Frequency Selective Surfaces (FSS) have been recently suggested for use in the design of electromagnetic meta-materials that behave like a Perfect Magnetic Conductor (PMC) (F. Yang, K. Ma, Y. Qian, and T. Itoh, IEEE Trans. Microwave Theory Tech., 47, 1509-1514, 1999). It has been shown that an FSS screen acting as a PMC can be used to improve the radiation characteristics of an antenna placed in close proximity to or in the same plane as such a surface (R. Coccioli, F. Yang, K. Ma, and T. Itoh, IEEE Trans. Microwave Theory Tech., 47, 2123-2130, 1999). However, one of the main drawbacks of these high impedance surfaces has their characteristically narrowband response.
Thus, there is a need for a method and technique for generating antenna configurations in an optimal manner. There is also a need for a technique for generating optimal patterns for other types of devices, e.g., a frequency selective surface with a high impedance capable of wideband or multiband performance.